Numerical Investigation of Centrifugal Blood Pump Cavitation Characteristics with Variable Speed

Teng Jing,Fangqun Wang,Wei Bao,Ling Zhou,Yujiao Cheng

doi:10.3390/pr8030293

Abstract

In this paper, the cavitation characteristics of centrifugal blood pumps under variable speeds were studied by using ANSYS-CFX and MATLAB software. The study proposed a multi-scale model of the “centrifugal blood pump—left heart blood circulation”, and analyzed the cavitation characteristics of the centrifugal blood pump. The results showed that the cavitation in the impeller first appeared near the hub at the inlet of the impeller. As the inlet pressure decreased, the cavitation gradually strengthened and the bubbles gradually developed in the outlet of the impeller. The cavitation intensity increased with the increase of impeller speed. The curve of the variable speeds of the centrifugal blood pump in the optimal auxiliary state was obtained, which could effectively improve the aortic pressure and flow. In variable speeds, due to the high aortic flow and pressure during the ejection period, the sharp increases in speeds led to cavitation. The results could provide a guidance for the optimal design of the centrifugal blood pump.

Highlights

Heart failure (HF) is the most fatal clinical syndrome due to heart dysfunction and insufficient blood supply
The maximum shear stress reached above 300 Pa, which did not include the wall shear stress generated by the fluid part of the centrifugal blood pump
Cavitation of the blood pump causes damage to the over-flow components, and destroys the blood cells, which is important in the safe operation of the ventricular assist device

Summary

Introduction

Heart failure (HF) is the most fatal clinical syndrome due to heart dysfunction and insufficient blood supply. With the increasing prevalence of cardiovascular and cerebrovascular diseases, ventricular assist devices have attracted attention as the main method for treating patients with advanced heart failure. Constant rotating speed control is frequently used to make the average aortic pressure and cardiac output of patients reach normal physiological levels. This assisted state is likely to cause aspiration and reflux, and is accompanied by many complications [1]. A blood pump variable speed control method is used to achieve the best auxiliary state under different heart failure conditions [2,3,4]. During the variable speed assist process, the transient of rotating speed can cause cavitation inside the blood pump

Methods

Results

Conclusion